/*!
 * Signature Pad v3.0.0-beta.3 
 * (c) 2018 Szymon Nowak | Released under the MIT license
 */

(function (global, factory) {
  typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
  typeof define === 'function' && define.amd ? define(factory) :
  (global.SignaturePad = factory());
}(this, (function () { 'use strict';

  var Point = (function () {
      function Point(x, y, time) {
          this.x = x;
          this.y = y;
          this.time = time || Date.now();
      }
      Point.prototype.distanceTo = function (start) {
          return Math.sqrt(Math.pow(this.x - start.x, 2) + Math.pow(this.y - start.y, 2));
      };
      Point.prototype.equals = function (other) {
          return this.x === other.x && this.y === other.y && this.time === other.time;
      };
      Point.prototype.velocityFrom = function (start) {
          return (this.time !== start.time) ? this.distanceTo(start) / (this.time - start.time) : 0;
      };
      return Point;
  }());

  var Bezier = (function () {
      function Bezier(startPoint, control2, control1, endPoint, startWidth, endWidth) {
          this.startPoint = startPoint;
          this.control2 = control2;
          this.control1 = control1;
          this.endPoint = endPoint;
          this.startWidth = startWidth;
          this.endWidth = endWidth;
      }
      Bezier.fromPoints = function (points, widths) {
          var c2 = this.calculateControlPoints(points[0], points[1], points[2]).c2;
          var c3 = this.calculateControlPoints(points[1], points[2], points[3]).c1;
          return new Bezier(points[1], c2, c3, points[2], widths.start, widths.end);
      };
      Bezier.calculateControlPoints = function (s1, s2, s3) {
          var dx1 = s1.x - s2.x;
          var dy1 = s1.y - s2.y;
          var dx2 = s2.x - s3.x;
          var dy2 = s2.y - s3.y;
          var m1 = { x: (s1.x + s2.x) / 2.0, y: (s1.y + s2.y) / 2.0 };
          var m2 = { x: (s2.x + s3.x) / 2.0, y: (s2.y + s3.y) / 2.0 };
          var l1 = Math.sqrt((dx1 * dx1) + (dy1 * dy1));
          var l2 = Math.sqrt((dx2 * dx2) + (dy2 * dy2));
          var dxm = (m1.x - m2.x);
          var dym = (m1.y - m2.y);
          var k = l2 / (l1 + l2);
          var cm = { x: m2.x + (dxm * k), y: m2.y + (dym * k) };
          var tx = s2.x - cm.x;
          var ty = s2.y - cm.y;
          return {
              c1: new Point(m1.x + tx, m1.y + ty),
              c2: new Point(m2.x + tx, m2.y + ty)
          };
      };
      Bezier.prototype.length = function () {
          var steps = 10;
          var length = 0;
          var px;
          var py;
          for (var i = 0; i <= steps; i += 1) {
              var t = i / steps;
              var cx = this.point(t, this.startPoint.x, this.control1.x, this.control2.x, this.endPoint.x);
              var cy = this.point(t, this.startPoint.y, this.control1.y, this.control2.y, this.endPoint.y);
              if (i > 0) {
                  var xdiff = cx - px;
                  var ydiff = cy - py;
                  length += Math.sqrt((xdiff * xdiff) + (ydiff * ydiff));
              }
              px = cx;
              py = cy;
          }
          return length;
      };
      Bezier.prototype.point = function (t, start, c1, c2, end) {
          return (start * (1.0 - t) * (1.0 - t) * (1.0 - t))
              + (3.0 * c1 * (1.0 - t) * (1.0 - t) * t)
              + (3.0 * c2 * (1.0 - t) * t * t)
              + (end * t * t * t);
      };
      return Bezier;
  }());

  function throttle(fn, wait) {
      if (wait === void 0) { wait = 250; }
      var previous = 0;
      var timeout = null;
      var result;
      var storedContext;
      var storedArgs;
      var later = function () {
          previous = Date.now();
          timeout = null;
          result = fn.apply(storedContext, storedArgs);
          if (!timeout) {
              storedContext = null;
              storedArgs = [];
          }
      };
      return function () {
          var args = [];
          for (var _i = 0; _i < arguments.length; _i++) {
              args[_i] = arguments[_i];
          }
          var now = Date.now();
          var remaining = wait - (now - previous);
          storedContext = this;
          storedArgs = args;
          if (remaining <= 0 || remaining > wait) {
              if (timeout) {
                  clearTimeout(timeout);
                  timeout = null;
              }
              previous = now;
              result = fn.apply(storedContext, storedArgs);
              if (!timeout) {
                  storedContext = null;
                  storedArgs = [];
              }
          }
          else if (!timeout) {
              timeout = window.setTimeout(later, remaining);
          }
          return result;
      };
  }

  var SignaturePad = (function () {
      function SignaturePad(canvas, options) {
          if (options === void 0) { options = {}; }
          var _this = this;
          this.canvas = canvas;
          this.options = options;
          this._handleMouseDown = function (event) {
              if (event.which === 1) {
                  _this._mouseButtonDown = true;
                  _this._strokeBegin(event);
              }
          };
          this._handleMouseMove = function (event) {
              if (_this._mouseButtonDown) {
                  _this._strokeMoveUpdate(event);
              }
          };
          this._handleMouseUp = function (event) {
              if (event.which === 1 && _this._mouseButtonDown) {
                  _this._mouseButtonDown = false;
                  _this._strokeEnd(event);
              }
          };
          this._handleTouchStart = function (event) {
              event.preventDefault();
              if (event.targetTouches.length === 1) {
                  var touch = event.changedTouches[0];
                  _this._strokeBegin(touch);
              }
          };
          this._handleTouchMove = function (event) {
              event.preventDefault();
              var touch = event.targetTouches[0];
              _this._strokeMoveUpdate(touch);
          };
          this._handleTouchEnd = function (event) {
              var wasCanvasTouched = event.target === _this.canvas;
              if (wasCanvasTouched) {
                  event.preventDefault();
                  var touch = event.changedTouches[0];
                  _this._strokeEnd(touch);
              }
          };
          this.velocityFilterWeight = options.velocityFilterWeight || 0.7;
          this.minWidth = options.minWidth || 0.5;
          this.maxWidth = options.maxWidth || 2.5;
          this.throttle = ('throttle' in options ? options.throttle : 16);
          this.minDistance = ('minDistance' in options ? options.minDistance : 5);
          if (this.throttle) {
              this._strokeMoveUpdate = throttle(SignaturePad.prototype._strokeUpdate, this.throttle);
          }
          else {
              this._strokeMoveUpdate = SignaturePad.prototype._strokeUpdate;
          }
          this.dotSize = options.dotSize || function () {
              return (this.minWidth + this.maxWidth) / 2;
          };
          this.penColor = options.penColor || 'black';
          this.backgroundColor = options.backgroundColor || 'rgba(0,0,0,0)';
          this.onBegin = options.onBegin;
          this.onEnd = options.onEnd;
          this._ctx = canvas.getContext('2d');
          this.clear();
          this.on();
      }
      SignaturePad.prototype.clear = function () {
          var ctx = this._ctx;
          var canvas = this.canvas;
          ctx.fillStyle = this.backgroundColor;
          ctx.clearRect(0, 0, canvas.width, canvas.height);
          ctx.fillRect(0, 0, canvas.width, canvas.height);
          this._data = [];
          this._reset();
          this._isEmpty = true;
      };
      SignaturePad.prototype.fromDataURL = function (dataUrl, options, callback) {
          var _this = this;
          if (options === void 0) { options = {}; }
          var image = new Image();
          var ratio = options.ratio || window.devicePixelRatio || 1;
          var width = options.width || (this.canvas.width / ratio);
          var height = options.height || (this.canvas.height / ratio);
          this._reset();
          image.onload = function () {
              _this._ctx.drawImage(image, 0, 0, width, height);
              if (callback) {
                  callback();
              }
          };
          image.onerror = function (error) {
              if (callback) {
                  callback(error);
              }
          };
          image.src = dataUrl;
          this._isEmpty = false;
      };
      SignaturePad.prototype.toDataURL = function (type, encoderOptions) {
          if (type === void 0) { type = 'image/png'; }
          switch (type) {
              case 'image/svg+xml':
                  return this._toSVG();
              default:
                  return this.canvas.toDataURL(type, encoderOptions);
          }
      };
      SignaturePad.prototype.on = function () {
          this.canvas.style.touchAction = 'none';
          this.canvas.style.msTouchAction = 'none';
          if (window.PointerEvent) {
              this._handlePointerEvents();
          }
          else {
              this._handleMouseEvents();
              if ('ontouchstart' in window) {
                  this._handleTouchEvents();
              }
          }
      };
      SignaturePad.prototype.off = function () {
          this.canvas.style.touchAction = 'auto';
          this.canvas.style.msTouchAction = 'auto';
          this.canvas.removeEventListener('pointerdown', this._handleMouseDown);
          this.canvas.removeEventListener('pointermove', this._handleMouseMove);
          document.removeEventListener('pointerup', this._handleMouseUp);
          this.canvas.removeEventListener('mousedown', this._handleMouseDown);
          this.canvas.removeEventListener('mousemove', this._handleMouseMove);
          document.removeEventListener('mouseup', this._handleMouseUp);
          this.canvas.removeEventListener('touchstart', this._handleTouchStart);
          this.canvas.removeEventListener('touchmove', this._handleTouchMove);
          this.canvas.removeEventListener('touchend', this._handleTouchEnd);
      };
      SignaturePad.prototype.isEmpty = function () {
          return this._isEmpty;
      };
      SignaturePad.prototype.fromData = function (pointGroups) {
          var _this = this;
          this.clear();
          this._fromData(pointGroups, function (_a) {
              var color = _a.color, curve = _a.curve;
              return _this._drawCurve({ color: color, curve: curve });
          }, function (_a) {
              var color = _a.color, point = _a.point;
              return _this._drawDot({ color: color, point: point });
          });
          this._data = pointGroups;
      };
      SignaturePad.prototype.toData = function () {
          return this._data;
      };
      SignaturePad.prototype._strokeBegin = function (event) {
          var newPointGroup = {
              color: this.penColor,
              points: []
          };
          this._data.push(newPointGroup);
          this._reset();
          this._strokeUpdate(event);
          if (typeof this.onBegin === 'function') {
              this.onBegin(event);
          }
      };
      SignaturePad.prototype._strokeUpdate = function (event) {
          var x = event.clientX;
          var y = event.clientY;
          var point = this._createPoint(x, y);
          var lastPointGroup = this._data[this._data.length - 1];
          var lastPoints = lastPointGroup.points;
          var lastPoint = lastPoints.length > 0 && lastPoints[lastPoints.length - 1];
          var isLastPointTooClose = lastPoint ? point.distanceTo(lastPoint) <= this.minDistance : false;
          var color = lastPointGroup.color;
          if (!lastPoint || !(lastPoint && isLastPointTooClose)) {
              var curve = this._addPoint(point);
              if (!lastPoint) {
                  this._drawDot({ color: color, point: point });
              }
              else if (curve) {
                  this._drawCurve({ color: color, curve: curve });
              }
              lastPoints.push({
                  time: point.time,
                  x: point.x,
                  y: point.y
              });
          }
      };
      SignaturePad.prototype._strokeEnd = function (event) {
          this._strokeUpdate(event);
          if (typeof this.onEnd === 'function') {
              this.onEnd(event);
          }
      };
      SignaturePad.prototype._handlePointerEvents = function () {
          this._mouseButtonDown = false;
          this.canvas.addEventListener('pointerdown', this._handleMouseDown);
          this.canvas.addEventListener('pointermove', this._handleMouseMove);
          document.addEventListener('pointerup', this._handleMouseUp);
      };
      SignaturePad.prototype._handleMouseEvents = function () {
          this._mouseButtonDown = false;
          this.canvas.addEventListener('mousedown', this._handleMouseDown);
          this.canvas.addEventListener('mousemove', this._handleMouseMove);
          document.addEventListener('mouseup', this._handleMouseUp);
      };
      SignaturePad.prototype._handleTouchEvents = function () {
          this.canvas.addEventListener('touchstart', this._handleTouchStart);
          this.canvas.addEventListener('touchmove', this._handleTouchMove);
          this.canvas.addEventListener('touchend', this._handleTouchEnd);
      };
      SignaturePad.prototype._reset = function () {
          this._lastPoints = [];
          this._lastVelocity = 0;
          this._lastWidth = (this.minWidth + this.maxWidth) / 2;
          this._ctx.fillStyle = this.penColor;
      };
      SignaturePad.prototype._createPoint = function (x, y) {
          var rect = this.canvas.getBoundingClientRect();
          return new Point(x - rect.left, y - rect.top, new Date().getTime());
      };
      SignaturePad.prototype._addPoint = function (point) {
          var _lastPoints = this._lastPoints;
          _lastPoints.push(point);
          if (_lastPoints.length > 2) {
              if (_lastPoints.length === 3) {
                  _lastPoints.unshift(_lastPoints[0]);
              }
              var widths = this._calculateCurveWidths(_lastPoints[1], _lastPoints[2]);
              var curve = Bezier.fromPoints(_lastPoints, widths);
              _lastPoints.shift();
              return curve;
          }
          return null;
      };
      SignaturePad.prototype._calculateCurveWidths = function (startPoint, endPoint) {
          var velocity = (this.velocityFilterWeight * endPoint.velocityFrom(startPoint))
              + ((1 - this.velocityFilterWeight) * this._lastVelocity);
          var newWidth = this._strokeWidth(velocity);
          var widths = {
              end: newWidth,
              start: this._lastWidth
          };
          this._lastVelocity = velocity;
          this._lastWidth = newWidth;
          return widths;
      };
      SignaturePad.prototype._strokeWidth = function (velocity) {
          return Math.max(this.maxWidth / (velocity + 1), this.minWidth);
      };
      SignaturePad.prototype._drawCurveSegment = function (x, y, width) {
          var ctx = this._ctx;
          ctx.moveTo(x, y);
          ctx.arc(x, y, width, 0, 2 * Math.PI, false);
          this._isEmpty = false;
      };
      SignaturePad.prototype._drawCurve = function (_a) {
          var color = _a.color, curve = _a.curve;
          var ctx = this._ctx;
          var widthDelta = curve.endWidth - curve.startWidth;
          var drawSteps = Math.floor(curve.length()) * 2;
          ctx.beginPath();
          ctx.fillStyle = color;
          for (var i = 0; i < drawSteps; i += 1) {
              var t = i / drawSteps;
              var tt = t * t;
              var ttt = tt * t;
              var u = 1 - t;
              var uu = u * u;
              var uuu = uu * u;
              var x = uuu * curve.startPoint.x;
              x += 3 * uu * t * curve.control1.x;
              x += 3 * u * tt * curve.control2.x;
              x += ttt * curve.endPoint.x;
              var y = uuu * curve.startPoint.y;
              y += 3 * uu * t * curve.control1.y;
              y += 3 * u * tt * curve.control2.y;
              y += ttt * curve.endPoint.y;
              var width = curve.startWidth + (ttt * widthDelta);
              this._drawCurveSegment(x, y, width);
          }
          ctx.closePath();
          ctx.fill();
      };
      SignaturePad.prototype._drawDot = function (_a) {
          var color = _a.color, point = _a.point;
          var ctx = this._ctx;
          var width = typeof this.dotSize === 'function' ? this.dotSize() : this.dotSize;
          ctx.beginPath();
          this._drawCurveSegment(point.x, point.y, width);
          ctx.closePath();
          ctx.fillStyle = color;
          ctx.fill();
      };
      SignaturePad.prototype._fromData = function (pointGroups, drawCurve, drawDot) {
          for (var _i = 0, pointGroups_1 = pointGroups; _i < pointGroups_1.length; _i++) {
              var group = pointGroups_1[_i];
              var color = group.color, points = group.points;
              if (points.length > 1) {
                  for (var j = 0; j < points.length; j += 1) {
                      var basicPoint = points[j];
                      var point = new Point(basicPoint.x, basicPoint.y, basicPoint.time);
                      this.penColor = color;
                      if (j === 0) {
                          this._reset();
                      }
                      var curve = this._addPoint(point);
                      if (curve) {
                          drawCurve({ color: color, curve: curve });
                      }
                  }
              }
              else {
                  this._reset();
                  drawDot({
                      color: color,
                      point: points[0]
                  });
              }
          }
      };
      SignaturePad.prototype._toSVG = function () {
          var _this = this;
          var pointGroups = this._data;
          var ratio = Math.max(window.devicePixelRatio || 1, 1);
          var minX = 0;
          var minY = 0;
          var maxX = this.canvas.width / ratio;
          var maxY = this.canvas.height / ratio;
          var svg = document.createElementNS('http://www.w3.org/2000/svg', 'svg');
          svg.setAttribute('width', this.canvas.width.toString());
          svg.setAttribute('height', this.canvas.height.toString());
          this._fromData(pointGroups, function (_a) {
              var color = _a.color, curve = _a.curve;
              var path = document.createElement('path');
              if (!isNaN(curve.control1.x) &&
                  !isNaN(curve.control1.y) &&
                  !isNaN(curve.control2.x) &&
                  !isNaN(curve.control2.y)) {
                  var attr = "M " + curve.startPoint.x.toFixed(3) + "," + curve.startPoint.y.toFixed(3) + " "
                      + ("C " + curve.control1.x.toFixed(3) + "," + curve.control1.y.toFixed(3) + " ")
                      + (curve.control2.x.toFixed(3) + "," + curve.control2.y.toFixed(3) + " ")
                      + (curve.endPoint.x.toFixed(3) + "," + curve.endPoint.y.toFixed(3));
                  path.setAttribute('d', attr);
                  path.setAttribute('stroke-width', (curve.endWidth * 2.25).toFixed(3));
                  path.setAttribute('stroke', color);
                  path.setAttribute('fill', 'none');
                  path.setAttribute('stroke-linecap', 'round');
                  svg.appendChild(path);
              }
          }, function (_a) {
              var color = _a.color, point = _a.point;
              var circle = document.createElement('circle');
              var dotSize = typeof _this.dotSize === 'function' ? _this.dotSize() : _this.dotSize;
              circle.setAttribute('r', dotSize.toString());
              circle.setAttribute('cx', point.x.toString());
              circle.setAttribute('cy', point.y.toString());
              circle.setAttribute('fill', color);
              svg.appendChild(circle);
          });
          var prefix = 'data:image/svg+xml;base64,';
          var header = '<svg'
              + ' xmlns="http://www.w3.org/2000/svg"'
              + ' xmlns:xlink="http://www.w3.org/1999/xlink"'
              + (" viewBox=\"" + minX + " " + minY + " " + maxX + " " + maxY + "\"")
              + (" width=\"" + maxX + "\"")
              + (" height=\"" + maxY + "\"")
              + '>';
          var body = svg.innerHTML;
          if (body === undefined) {
              var dummy = document.createElement('dummy');
              var nodes = svg.childNodes;
              dummy.innerHTML = '';
              for (var i = 0; i < nodes.length; i += 1) {
                  dummy.appendChild(nodes[i].cloneNode(true));
              }
              body = dummy.innerHTML;
          }
          var footer = '</svg>';
          var data = header + body + footer;
          return prefix + btoa(data);
      };
      return SignaturePad;
  }());

  return SignaturePad;

})));
